diff --git a/src/_Problems_/max-consecutive-1s/index.js b/src/_Problems_/max-consecutive-1s/index.js
index 18a5058a..7720370c 100644
--- a/src/_Problems_/max-consecutive-1s/index.js
+++ b/src/_Problems_/max-consecutive-1s/index.js
@@ -22,3 +22,5 @@ function findMaxConsecutive1s(arr) {
 if (count> max) max = count;
 return max;
 }
+
+module.exports = { findMaxConsecutive1s };
diff --git a/src/_Problems_/max-consecutive-1s/max-consecutive-1s.test.js b/src/_Problems_/max-consecutive-1s/max-consecutive-1s.test.js
new file mode 100644
index 00000000..e37abdae
--- /dev/null
+++ b/src/_Problems_/max-consecutive-1s/max-consecutive-1s.test.js
@@ -0,0 +1,20 @@
+const { findMaxConsecutive1s } = require(".");
+
+describe("Find maximum numbers of consecutive 1s", () => {
+ it("returns 1 if there is only one number 1", () => {
+ expect(findMaxConsecutive1s([1])).toEqual(1);
+ });
+
+ it("return the appropriate count for a large array", () => {
+ const largeArray = [0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1];
+ expect(findMaxConsecutive1s(largeArray)).toEqual(5);
+ });
+
+ it("returns count 0 if there is no number 1", () => {
+ expect(findMaxConsecutive1s([0, 2, 3, 9, 0])).toEqual(0);
+ });
+
+ it("does NOT count negative 1s", () => {
+ expect(findMaxConsecutive1s([1, 1, 0, -1, -1, -1])).toEqual(2);
+ });
+});
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